Alloy



Aug. l23, 1938. F. R. HENSEL ET AL ALLOY Filed June l5, 1957 m j. m f

Patented Aug. 23, 1938 UNITED STATES PATENT OFFICE ALLOY .Franz R. Hensel and Earl I. Larsen, Indianapolis, Ind., assignors to P. R. Mallory & Co., Inc., Indianapolis, Ind., a corporation of Delaware Application June 15, 1937, Serial No. 148,284 s claims. (ci. 14s-s2) higher degree than has heretofore been possible.

lo Another object is to produce a copper alloy which has an excellent combination of hardness, electrical conductivity and resistance to annealing.

Specic objects are the provision of improved u copper-zirconium-magnesium alloys especially suitable for fabrication intowelding electrodes, high strength sand castings for use with cylinder heads, pistons and other parts of internal combustion engines, commutator segments, trolley 20 Wires, collector rings, switch plates, bolts, nuts and in general for all uses where high strength and/or high conductivity are required at elevated temperatures.

Other objects of the invention will be apparent from the following description taken in connection with the appended claims.

The present invention comprises a combination of elements, methods of manufacture and the product thereof brought out and exemplified 80 in the disclosure hereinafter set forth, the scope of the invention being indicated in the appended claims.

In the drawing:

Fig. 1 is a graph illustrating the eifect of cold 35 working of the alloy referred to in Fig. 2 after aging.

Fig. 2 is a graph showing a curve illustrating the improvement during age hardening in the hardness and electrical conductivity of an alloy composed of l Percent Magnesium 0.45 zirconium 0.86 Balance substantially all copper Figure 3 is a graph showing a curve illustrating the improvement in hardness during aging of an alloy composed of Percent MagnesiumL 1.33 zirconium 1.13 Balance substantially all copper alloy. vof copper, magnesium and zirconium in the following permissible range of -proportionsz f Percent Magnesium 0.05 to 3 zirconium -M 0.1 to 5 Balance substantially copper The preferred range of proportions are as follows:y

. Percent Magnesium 0.1m 1.5 1 Zirconium 0.1 to2 Balance ubstantially copper In some instances it may be desirable for certain uses to effect an improvement in the alloy by adding small percentages of additional ingredients, such as silver, zinc, tin, cadmium, calcium, lithium, silicon, titanium, beryllium `and aluminum.

In carrying out the present invention a copper magnesium alloy may iirst be made according to the conventional alloy making procedure of the prior art and then the zirconium may be added.

It is also possible, however,'to produce a copper-zirconium alloy first by melting down the copper and adding the zirconium in the form of a hardener alloy which may contain anywhere from 5-50'% zirconium. This hardener alloy can be either a pressed product or a pressed and sintered product or a melted product. 'I'he mag- 30 y nesium is preferably added also in the form of a hardener alloy. Magnesium, in addition to its function as an alloying ingredient, will also act as a very strong deoxidizer and therefore with this new combination of copper magnesium zirconium it is possible to produce very sound castings.

After the alloy has been prepared according to such alloying methods as described above, the heat treatment may be carried out as follows: 0

The alloy in the form of a billet or a sand casting or any other form, is raised in temperature above 700 degrees C., and preferably to a temperature Within the range of 800-1000 degrees C.

'I'he alloy is then quenched from this high tem- 5 perature and subsequently aged at a temperature below 700 degrees C., and preferably in the range between 400-600 degrees C. It is possible to cold work the alloy after the complete heat treatment.

v In manyv instances, we have found it advisable cold work the alloy after quenching, then subsequently age it, with or without further cold working after aging. We have found it possible to eliminate quenching` operations and cold work the material after hot working and subsequently This is of great importance whenever the alloyl is being used at elevated temperatures. Usually copper base alloys, particularly when cold worked, lose their hardness at elevated temperatures and it is necessary to apply additional cold work toraise the hardness to the original value. At the same time, the elastic and tensile properties are decreased considerably. Therefore, ,copper alloys have been very limited as structural parts in machinery which is run at elevated temperatures. The new alloy described in the present disclosure provides a material, which on account of its strength at elevated temperature and its good thermal conductivity, will provide an excellent material for such structural parts. Furthermore, alloys of the type described have a high resistance to oxidation and to corrosion.

While, for instance, it is necessary to add as much as 10% aluminum to obtain a certain oxidation resistance of a copper base alloy, the combined presence oi. 2% magnesium and zirconium will provide the same resistance.

Alloys prepared as indicated above are well suited for the manufacture of any type of castings, such as sand castings, chill castings or permanent mold castings. The alloys are further well suited for such manufacturing processes as extruding, forging, rolling and drawing. On account of the combination of high hardness, high electrical and high thermal conductivity,

the material can be used for electrical parts of any description.

Another important use for these high strength copper base alloys is in the fabrication of parts of internal combustion engines, such as automobile engines where high heat conductivity is needed.

While the present invention as to its objects and advantages has been described herein as carried out in specic embodiments thereof, it is not desired to be limited thereby, but it is intended to cover the invention broadly, within the spirit and the scope of the appended claims.

What is claimed is:

1. An alloy containing about 0.05 to 3.0% magnesium, 0.1 to 10% zirconium, and the remainder copper.

2. An age hardened alloy containing about 0.05 to 3% magnesium, 0.1 to 10% zirconium, and the remainder substantially all copper, characterized by a combination of high hardness and high electrical conductivity and further characterized by' the ability to maintain its hardness and high electrical conductivity at temperatures in the order of 500 C.

I 3. An electrical current carrying member composed of about 0.05 to 3% magnesium, 0.1 to 10% zirconium, and the remainder copper.

4. A heat conducting member composed of about 0.05 to 3% magnesium, 0.1 to 10% zirconium, and the remainder copper.

5. A welding electrode composed of about 0.05 to 3.0% magnesium, 0.1 to 10% zirconium, and the remainder substantially all copper, characterized by a combination of high hardness and high electrical conductivity, and further characterized by the ability to maintain its hardness and high conductivity at temperatures in the order oi' 500 C.

FRANZ R. HENSEL.

EARL I. LARSEN. 

